Track for high speed acceleration sleds



Dec. 19, 1961 R. LEES 3,013,725

TRACK FOR HIGH SPEED ACCELERATION SLEDS Filed May 27, 1959 3 Sheets-Sheet 1 I K /A 7 IN VEN TOR.

F036]! lees Dec. 19, 1961 R. LEES 3,013,725

TRACK FOR HIGH SPEED ACCELERATION SLEDS Filed May 27, 1959 3 Sheets-Sheet 2 INVENTOR. P0582 flees Dec. 19, 1961 R; LEES TRACK FOR HIGH SPEED ACCELERATION SLEDS 3 Sheets-Sheet 3 Filed May 27, 1959 INVENTOR. F0262? Zees BY United States Patent Office 3,013,725 Patented Dec. 19, 1961 3,013,725 TRACK FOR HIGH SPEED ACCELERATION SLEDS Robert Lees, Chadds Ford, Pa., assignor to All American Engineering Company, Wilmington, Del., a corporation of Delaware Filed May 27,1959, Ser. No. 816,176 9 Claims. (Cl. 238-2) The present invention relates to a track arrangement and more particularly to a novel track foundation for high speed acceleration sleds and like test equipment.

Heretofore track foundations for high speed sleds or wheeled carts travelling thereover at speeds approaching and/or exceeding the speed of sound have lacked durability and after one or two test operations became displaced sufficiently to cause the tracks to deviate from required straightness and alignment, thereby interfering with the acceleration studies of test runs and making the same extremely dangerous for manned tests.

Accordingly, it is an object of this invention to provide a novel self-compensating track base, whereby a straight and level track is maintained for acceleration studies.

A more specific object is to provide a novel track foundation for a floating tensioned track arrangement, whereby the weight per unit length for the track and the track foundation floatation material or ballast means is accurately controlled together with the unit area of the floatation material, so that when floated in said material, the track will lie in a horizontal plane and lateral straightness will be maintained by applying a reverse tension to the opposite ends of the track.

Another object is to provide a track and a floatation base structure therefor with baffle means immersed in the floatation fluid adapted to reduce vibration of the track with respect to the fluid supporting the same or by waves set up in the fluid during use for acceleration studies.

A further object is to provide a thermoplastic track foundation for parallel track structure adapted to be heated to recondition and return the track to required straightness from any deviation therefrom.

Still further objects and improvements will be apparent from the following description when read in conjunction with the following drawings, wherein:

FIG. 1 is a top plan view of a section of track foundation and track structure according to one embodiment of the present invention;

FIG. 2 is a transverse section view taken along section line'22 of FIG. 1;

FIG. 3 is a second embodiment of the invention showing a transverse section taken across the track installation; and

FIG. 4 is a third embodiment of the invention in transverse cross section, illustrating a track foundation of thermoplastic material and means for alternately molding and remolding said material;

FIG. 5 is a transverse section view taken through a fourth embodiment of composite track structure, showing a sled mounted on the same; and

FIG. 6 is a transverse section view taken through a fifth embodiment of the invention showing a high speed sled mounted thereon with novel track engaging slipper means.

Referring in detail to the drawings, and first with particular reference to FIGS. 1 and 2, the present invention comprises a pair of spaced parallel elongated trench members 10 and 11 formed in concrete or in hard clay or dirt, generally designated 12. Each trench may be lined with plastic 13 to thereby form elongated water troughs in each trench.

These water troughs 10 and 11 are filled with liquid,

such as water or water and suitable anti-freeze to provide a predetermined liquid level line 14, see FIG. 2, when the respective track sections 15 and 16 are floated in the troughs. The fluid or water level in each trough is equalized by providing a transverse connecting trench or trough 10a, see FIG. 1.

These track sections each comprises a plurality or string of floatation pads or sections formed of suitable floatation material 17, such as poly-urethane sponge, and metal rail sections 18, preferably of steel molded in the floatation material. The rail sections 18 comprise wheel or slipper engaging V-grooved heads 19 connected by a vertical web 20 to a base or foot portion 21.

Now, with specific reference to FIG. 1, the floating track sections are welded or molded together in straight elongated lengths of track and are put under tension stress by suitable means, such as tensioning turnbuckles 21 and 22 at each end of each composite flotation track section. The turnbuckles are secured to gage links, such a a crosshe-ad or crossbar 23 welded to each metal rail end and each gage link carries a screw bolt of the respective turnbuckles, which bolts project therefrom, while the other respective screw bolts at the opposite ends of the said turnbuckles are anchored in a suitable structure or wall 24 at the end of the track. Each opposite end of the installation includes the same tensioning arrangement. The gage links 23 keep the track sections of each spaced trough in accurate spaced parallel relation. When the track assemblies 17 are in floatation position in their respective liquid filled troughs 10 and 11, a smooth straight sled track that will not require alignment or straightening due to shifts in the foundation is provided.

A second embodiment of the invention is illustrated in FIG. 3 of the drawings, and includes the structure of the troughs 10 and 11 of embodiment one with a plurality of lateral baffles 25 mating with the bottom of the trench and the exterior of the respective troughs. Also, the float ation material of the track assemblies are formed with longitudinal fins 26, 27 and 28, 29 on each side thereof, which extend with their respective surfaces in a horizontal plane, to thereby reduce possible vertical oscillations of the track 17 with respect to the fluid supporting it in the said troughs caused by vibration or by waves set up in the fluid.

A third embodiment is illustrated in FIG. 4 wherein the troughs 10 and 11 are filled with thermoplastic material 30, such as sulphur, for example, to a predetermined level established by the track means 17 when floated in the trough, while said material is in a fluid state due to heating means, such as steam pipes 31 and 32. The pipes are mounted in a sump portion 33 formed in the respective troughs.

The thermoplastic material is such that it may be melted by the superheated steam pipes and the floatation track 17 is tensioned to assure straigh tness and the thermoplastic material is permitted to cool and to harden. The device is then ready for operation. During usage, when the foundation under the thermoplastic material shifts allowing the track to deviate from an accurate straightness, it is only necessary to remelt the thermoplastic material and tension the rails or tracks with the tensioning turnbuckles to restraighten them. Then, by allowing this material to cool and harden again, the device is again prepared for operation.

Another embodiment of the invention is illustrated in FIG. 5. In this form, the track rails 18a are formed like an I-beam and the floatation pads 17a are formed with an elongated countersunk channel 35, thereby exposing the T-head of the rail 18a molded therein for engagement by runners 36 of a high speed sled 37.

The pads 17a are formed around the rails 18a and include side horizontal thin metal fins 38 to reduce vertical track movements. As previously stated, the composite track assembly consisting of the metal beam and plastic floatation material must have a uniform weight per unit length and a uniform cross sectional area. Any deviations in the unit weight can be corrected by adding and subtracting ballast, water for example, as required in the troughs.

Another embodiment is illustrated in FIG. 6 showing a high speed sled 38a, With a track rail 39' formed of split aluminum tube. The test sled 33 is supported on round slippers 39a as shown, and these slippers may be separated from the track tube bores by an air bearing to prevent excessive track wear.

The track rails 39 are formed with an elongated longitudinal bore or conduit 40 in the bottom portion to provide for passage of superheated steam to melt the thermoplastic ballast material 41 in the troughs 42 and 43.

The use and operation of all embodiments is basically the same. For example, in operation, the acceleration cart 34 or sled will be positioned at one end of the track for subsequent propulsion thereover. It may be either a live or a deadload.

Heavy carts or sleds may require additional jacks or supports at the battery positioning end of the installation in order to reduce deflection of the track. However, once the sled or cart is moving, the deflection possibilities will decrease with increasing velocity, since the effective mass or extent of rail that must be accelerated downward will increase, so that at high speed there will be negligible vertical motion of the track in floatation position in the troughs.

The presence of a trough filled with water also provides for a convenient Water brake, not shown, for deceleration of the sled or cart, if desired.

Thus, there is provided a smooth track that will minimize unwanted acceleration input to a sled or cart for accurate acceleration studies. Also, such track is inexpensive, level, and easy to maintain in good operative condition.

While the present invention is described in detail and only a few embodiments thereof are illustrated for practicing the invention, it is to be expressly understood that the apparatus illustrated is for illustrative purposes only and the invention is not necessarily limited to such specific apparatus. To determine the Scope of this invention, reference should be had to the appended claims.

What is claimed is:

1'. A track installation comprising a solid base structure, elongated spaced substantially parallel troughs containing liquid formed in said base structure, an elongated floatable body in each of said troughs floating in said liquid, and a track rail molded in said body, said track rail comprising an exposed head portion extending longitudinally along the top surface of said body.

2. A track installation comprising an elongated trough containing liquid, an elongated floatable body in said trough floating in said liquid, and a track rail molded in said body and comprising an exposed rail portion extending longitudinally along" the top surface of said body, said body having fixed laterally extending fins projecting therefrom in a horizontal plane in the liquid said fins being non-pivoted and relatively thinner than said body.

3. A track installation comprising an elongated trough containing liquid, an elongated floatable body in said trough floating in said liquid, and a track rail molded in said body and comprising an exposed rail portion extending longitudinally along the top surface of said body, said track rail and said molded body being secured together in straight alignment and positioned in spaced parallel relation in their respective elongated troughs containing liquid, gage bars secured across the ends of said respective spaced track rails and tension means for said track rail and molded body floatation support secured to each of said gage bars at each end of the same.

4. A composite track for high speed sled test runs comprising a solid base means, elongated spaced substantially parallel troughs formed in said base means, a floatation means, a track rail carried by said floatation means, and liquid ballast in said troughs floating said floatation means and said track carried thereby in a horizontal planev 5. A composite track for high speed sled test runs c0111- prising a floatation means, a track rail carried by said means, a trough, thermoplastic ballast in said trough, said floatation means resting on said ballast in said trough and heater means positioned in said trough for melting said ballast, to thereby provide fluidity to said ballast to cause said floatation means and said tracrc rail carried thereby to float in the melted ballast.

6. A composite track for high speed sled test runs comprising a floatation means, a track rail molded in said means and carried by said means, a trough, and liquid ballast in said trough floating said floatation means and said track carried thereby in a horizontal plane, said floatation means being formed with fixed laterally projecting stabilizing means immersed in said liquid ballast, said fins being rigid with respect to said floatation means and relatively thinner than the thickness of said floatation means.

7. A composite track assembly in combination with a trough and a track assembly supporting ballast which ballast is fluid at certain temperatures, said track assembly comprising an elongated rail supported by the ballast, and heat generating means for varying the fluid supporting characteristics of said ballast to thereby control the straightness of said track assembly.

8. A composite track for high speed acceleration test sled runways comprising a tubular track having a lower portion formed with a steam conduit extending longitudinally thereof, a thermoplastic support for said track, and a trough for said thermoplastic support, said trough being countersunk in the surface of the test sled runway.

9. A composite track assembly in combination with a trough and a track assembly supporting ballast, said track assembly comprising an elongated rail supported by the ballast, and means for varying the supporting characteristics of said ballast to thereby control the straightness of said track assembly, said supporting ballast being a thermoplastic and said heat generating means being steam.

ReferencesCited in the file of this patent UNITED STATES PATENTS 1,367,115 Blondel Feb. 1, 1921 2,321,677 Higgins June 15, 1943 2,692,101 Doolittle et a1 Oct. 19, 1954 2,875,953 Weber et al Mar. 3, 1959 

